Urethral stenosis in infants

Urethral stenosis is a common disease among infants and also a disease that has a great impact on the health of the infant's urinary system. There are many reasons that lead to urethral stenosis in infants, such as trauma, inflammation, genetics or medical accidents. Different measures need to be taken for urethral stenosis caused by different reasons. Below we will introduce in detail the causes of urethral stenosis in children.

1. Traumatic urethral stricture

Traumatic urethral stricture is actually a late complication of urethral trauma and is the most common. The most common urethral stricture is in the bulbar urethra, accounting for about 50%, followed by the posterior urethra, about 40%, and the least in the pendulous urethra, accounting for 10%. Trauma includes penetrating injuries (gunshot wounds, stab wounds), blunt injuries (straddle injuries, penile contusions), and crush injuries (pelvic fractures). The first two types of injuries often injure the anterior urethra, and the latter type of injury can injure the posterior urethra in 10% of cases. They are shear injuries of the membranous part or lacerations between the bulbar and membranous parts, and are often combined injuries. Some patients with straddle injuries did not seek medical treatment in time because their injuries were minor, and most of them developed symptoms of urethral stenosis 5 to 7 years later. Some patients were not discovered until their condition required a urinary catheter.

2. Iatrogenic injury

It is mostly located between the junction of the anterior urethra, scrotum and penis and the bulbar urethra. It is caused by instrumentation in the urethra, urethral compression necrosis, or chemical stimulation from an indwelling urinary catheter. Recently, it has been found that damage to the urethral mucosa by pancreatic enzymes in the urine after pancreatic transplantation can cause urethral stenosis. Prolonged endoscopic operation time is the main cause of iatrogenic urethral stenosis. When a urinary catheter is left in place, in addition to the chemical toxicity of the catheter, bacteria are easily attached to the surface of the catheter, causing retrograde infection. Compression of the catheter at the physiological curvature causes ischemic necrosis, which can easily lead to stenosis.

3. Inflammatory

Inflammatory urethral stricture is caused by specific or nonspecific urethral infection. Among specific infections, gonorrheal urethral stricture is more common, followed by tuberculosis. Among nonspecific infections, urethral stricture of the external urethral orifice and penile urethra caused by repeated inflammation of the foreskin and glans is more common. Recurrent gonococcal urethritis causes extensive scar tissue to form on the urethral wall, which may present as segmental or long-segment urethral stenosis. The scar penetrates deep into the entire urethra and even the surrounding tissues of the urethra, causing urethral lumen obstruction, which is quite difficult to treat clinically.

4. Congenital

Congenital stenosis of the external urethral orifice is the most common, and urethral valves, hypertrophy of the seminal vesicles, congenital narrowing of the urethral lumen, phimosis, etc. can also be seen.

Urethral stricture can be divided into simple urethral stricture and complex urethral stricture according to the length of the stricture and the presence or absence of complications. Complex urethral strictures include: stricture length exceeding 3 cm in the anterior urethra and exceeding 2 cm in the posterior urethra; more than two stricture segments; accompanied by stones, diverticula, inflammatory polyps, urethritis or periurethritis; chronic urine leakage with the presence of a false passage; urethral sphincter dysfunction; severe pelvic deformity or concurrent pubic osteomyelitis and high urethral stricture close to the bladder neck.